Is Marijuana itself bad for you?

Ive been searching around the internet for an answer and i cant seem to find one so i guess ill be the first to post. Is marijuana itself bad for you? as in ingesting it like eating a brownie or eating a firecracker for those of you who know what those are. Does ingesting marijuana have any negative effects on the body, health, i know it can cause short term but memory can be regained in 1-2 weeks after stoping use. Also can it harm your stamina? Im a runner and i quit smoking a loong time ago but i still ingest marijuana occasionally. I hold the record mile for my county and am looking at scholarships but i want to know if marijuana itself can harm my running capabilities. It will be no problem to completely stop using marijuana.